Generally speaking, water purification is the process of removing impurities and contaminants from impure or contaminated water. Although there is more than one method to clean water for drinking or other purposes, they can be divided into physical methods like precipitation or filtration and chemical method such as chlorination. The application of ozone for water purification has become more and more widespread in the last three decades. In many European cities, ozone water purification has become an important means of removing pollutants from water for deep purification of drinking water.
Ozone has a strong oxidizing capacity. Its reaction speed is very fast when applied in disinfection and sterilization. When dissolved in water, ozone will quickly oxidize harmful microorganisms and other harmful ingredients, so as to realize the purification of water. Ozone has a short half-life about 30 minutes. Ozone dissolved in water will soon go back to oxygen when the reaction is finished, so there will be no residue left. In the following, let’s take a look at some of the applications and characteristics of ozone water purification.
1. Industrial Wastewater Treatment
Industrial wastewater treatment is a difficult task for many cities. In recent years, some organic pollutants which are difficult to degrade or toxic such as pesticides, synthetic detergents and some dyes have appeared in industrial wastewater. Ozone can oxidize a variety of organic and inorganic substances, remove ozone sensitive components such as phenols, benzene-containing compounds, cyanide, nitrite, organic nitrogen compounds, etc. In addition, ozone’s oxidative bleaching effect can significantly bring down the chroma of water. Not only that, ozone can also kill algae in water and stop its development to ensure the purity of industrial water.
2. Drinking Water Treatment
Compared with traditional chlorination treatment, ozone is better at removing harmful elements such as manganese and iron, as well as bacteria and viruses in water. Ozone can convert cyanide, phenol and other toxic and harmful substances in water into harmless substances. Ozone can also flocculate with manganese, iron and other metal elements in water to form high-priced precipitate, which makes it easy to be removed. As a good oxidant, ozone can even effectively remove some viruses and spores that are resistant to chlorination process.
3. Keep the Original Taste of Water
Some people tend to use special water softeners that contain salt to treat harder water. This does reduce the hardness of the water, but the addition of salt will surely change its taste. For people who are sensitive to salt, drinking water containing salt for long time is unacceptable. Applying ozone to treat water will not change its original taste. Ozone will remove the contaminants within the water when dissolved, but it will not create any chemical components or change the pH of the water. There will be no residue left after the purification process is completed.
4. A Healthier Sterilization Method
Nowadays, chlorination is still the main solution for tap water treatment in many countries and regions in the world. In fact, chlorinated water used in swimming pools may cause irritation to our eyes. There is also a link between chlorination of drinking water and the incidence of cancer. Chlorine can react with natural organic matter in water to produce obvious degenerative organic by-products such as chloroform, which can cause also health risks. The application of ozone for drinking water treatment is the best alternative for chlorination to solve these concerns.
5. Reduce Application Risk
In the chlorination treatment of drinking water, it is unavoidable to transport, store and use highly toxic liquid chlorine or sodium hypochlorite, so there will be certain safety risks. Compared with chlorination, ozone gas used for ozone water purification is prepared and used just in time, thus avoiding these potentially dangerous operation steps in chlorination treatment.
Ozone is recognized as an efficient and safe bactericidal and bacteriostatic method because of its active chemical properties. Ozone is widely applied in water treatment in daily life, chemical industry and environmental protection, etc. Today, many water plants around the world still use the same processes of precipitation, filtration and chlorination that have not changed significantly in the past over 200 years. In the future, as the characteristics of ozone are more familiar to the public, there will be more ozone water purification operation to solve the problems of industrial and urban wastewater treatment and to improve the quality of drinking water for every family.